1. Field of the Invention
The present invention relates to an overhead transport apparatus, more particularly, to an overhead transport apparatus installed on a ceiling of a building to transport articles.
2. Description of the Related Art
Generally, an overhead transport apparatus includes a guide rail unit installed on a ceiling of a building such as a hospital or a semiconductor factory, and a transport vehicle adapted to hold an article, such as a semiconductor and to move along a guide rail.
The guide rail unit of the transport apparatus generally includes a main rail and a branch rail branching off the main rail.
A conventional overhead transport apparatus including a guide rail unit, and a moving body supported and guided by the guide rail unit and moving on the guide rail unit, is disclosed in Korean Patent Application No. 2001-56773.
The guide rail unit includes a pair of rail members. Each rail member is formed with an upward wheel supporting plane and an inward roller guide plane. The guide rail unit includes a linear rail part and a branch rail part branching off the linear rail part. A linear guide member and a branch guide member are installed in a joint part of the linear rail part and the branch rail part.
The moving body is provided with a wheel supported and guided by the wheel supporting plane, a side guide roller guided by the roller guide plane, and a direction regulating roller guided by a transverse guide part of the branch guide member to regulate a direction of the moving body.
The direction regulating roller moves freely between a position corresponding to the linear guide member and a position corresponding to the branch guide member by a moving means to move the direction regulating roller right and left.
The moving means includes a supporter connected to the direction regulating roller, a guide load guiding the supporter, a cam roller having a spiral groove engaged with a cam moving part provided in the supporter, and a driving part (driving motor) to drive the cam roller.
Thus, the direction regulating roller provided in the conventional transport equipment moves right and left by the moving means and is selectively guided to the linear guide member or the branch guide member, to thereby move the moving body toward the linear rail part or the branch rail part.
However, according to the conventional transport equipment, the linear guide member and the branch guide member are respectively provided along the linear rail part and the branch rail part in the joint part of the linear route and the branch rail, thereby making the structure more complex. Also, the configuration of the moving means to move the direction regulating roller right and left so that the direction regulating roller can be guided to the linear guide member or to the branch guide member is complex. Accordingly, there are problems in that failures and repair costs are increased, as well as there being increased manufacturing costs.